Release Notes

08 October, 2016: Release 2.6.5 available

03 September, 2016: Release 3.0.0-alpha1 available

This is the first alpha in a series of planned alphas and betas leading up to a 3.0.0 GA release.
The intention is to "release early, release often" to quickly iterate on feedback collected from downstream users.

Please note that alpha releases come with no guarantees of quality or API stability, and are not intended for
production use.

23 September, 2015: Release 2.6.1 available

06 July, 2015: Release 2.7.1 (stable) available

A point release for the 2.7 line. This release is now considered
stable.

Please see the
Hadoop 2.7.1 Release Notes for the list of 131 bug fixes and
patches since the previous release 2.7.0. Please look at the
2.7.0 section below for the list of enhancements enabled by this
first stable release of 2.7.x.

21 April 2015: Release 2.7.0 available

Apache Hadoop 2.7.0 contains a number of significant
enhancements. A few of them are noted below.

IMPORTANT notes

This release drops support for JDK6 runtime and works with
JDK 7+ only.

This release is not yet ready for production use. Critical
issues are being ironed out via testing and downstream
adoption. Production users should wait for a 2.7.1/2.7.2
release.

Hadoop Common

HADOOP-9629
- Support Windows Azure Storage - Blob as a file
system in Hadoop.

14 February, 2013: Release 2.0.3-alpha available

This release delivers significant major features and stability
over previous releases in hadoop-2.x series:

QJM for HDFS HA for NameNode

Multi-resource scheduling (CPU and memory) for YARN

YARN ResourceManager Restart

Significant stability at scale for YARN (over 30,000 nodes
and 14 million applications so far, at time of release)

This release, like previous releases in hadoop-2.x series is
still considered alpha primarily since some of APIs
aren't fully-baked and we expect some churn in future.
Furthermore, please note that there are some API changes from
previous hadoop-2.0.2-alpha release and applications will need
to recompile against hadoop-2.0.3-alpha.

27 Feb, 2012: release 0.23.1 available

This is the second alpha version of the hadoop-0.23 major
release after the first alpha 0.23.0. This release
has significant improvements compared to 0.23.0 but should still
be considered as alpha-quality and not for production use.

hadoop-0.23.1 contains several major advances from 0.23.0:

Lots of bug fixes and improvements in both HDFS and MapReduce

Major performance work to make this release either match
or exceed performance of Hadoop-1 in most aspects of both
HDFS and MapReduce.

Several downstream projects like HBase, Pig, Oozie, Hive
etc. are better integrated with this release

11 Nov, 2011: release 0.23.0 available

This is the alpha version of the hadoop-0.23 major
release. This is the first release we've made off
Apache Hadoop trunk in a long while. This release is
alpha-quality and not yet ready for serious use.

hadoop-0.23 contains several major advances:

HDFS Federation

NextGen MapReduce (YARN)

It also has several major performance improvements to
both HDFS and MapReduce.

23 August, 2010: release 0.21.0 available

This release contains many improvements, new features, bug
fixes and optimizations. It has not undergone testing at scale and should not be considered stable or suitable for production.
This release is being classified as a minor release, which means that it should be API compatible with 0.20.2.

24 February, 2009: release 0.19.1 available

This release contains many critical bug fixes, including some data loss issues.
The release also introduces an incompatible change by disabling the
file append API (HADOOP-5224)
until it can be stabilized.

29 October 2007: release 0.15.0 available

When upgrading an existing HDFS filesystem to a 0.15.x
release from an earlier release, you should first start HDFS
with 'bin/start-dfs.sh -upgrade'. See the Hadoop
Upgrade page for details.

19 October, 2007: release 0.14.3 available

This release fixes critical bugs in release 0.14.2.

4 September, 2007: release 0.14.1 available

New features in release 0.14 include:

Better checksums in HDFS. Checksums are no longer
stored in parallel HDFS files, but are stored directly by
datanodes alongside blocks. This is more efficient for the
namenode and also improves data integrity.

Pipes: A C++ API for MapReduce

Eclipse Plugin, including HDFS browsing, job
monitoring, etc.

File modification times in HDFS.

There are many other improvements, bug fixes, optimizations
and new features. Performance and reliability are better than
ever.

Note

When upgrading an existing HDFS filesystem to a 0.14.x
release from a 0.13.x or earlier release, you should first
start HDFS with 'bin/start-dfs.sh -upgrade'. See the Hadoop
0.14 Upgrade page for details.